1. Field of the Invention
The invention relates to circuits which automatically turn off the head and tail/park lights of an automobile or other vehicle when turning off the ignition switch. This prevents the inadvertent discharge of the battery should the operator fail to separately turn off the head and tail/park lights when turning off the ignition switch. The invention also relates to circuits which automatically turn on the head and tail/park lights in conjunction with turning on the vehicle windshield wiper switch.
2. State of the Art
If vehicle headlights are on during daylight hours, it is common to forget to turn the lights off when the vehicle ignition is turned off. Some vehicles have buzzers or other audio alarms to warn a driver leaving a vehicle that the lights are still on, but in some cases drivers may not hear or pay attention to such audio alarms. A usual result of leaving lights on when the vehicle is parked and the ignition is turned off is that the lights drain the vehicle battery so it cannot be started later.
A number of circuits and devices are currently available which automatically turn off the head and tail/park lights when turning off the ignition switch. However, none of these circuits and devices include a circuit which monitors the operation of the circuit or device and include a bypass circuit which automatically engages, if the primary light control circuit should fail, thereby restoring the head and tail/park lights.
There are also a number of circuits and devices which automatically turn on the head and tail/park lights in combination with the windshield wiper switch. Several states now have laws requiring that the vehicle lights be turned on in combination with the windshield wipers. This is presumably a safety feature so lights are turned on during stormy weather. However, none of these circuits and devices include a provision to automatically turn off the head and tail/park lights when turning off the ignition switch regardless of whether the light switch is in the on or the off position.